A treadmill is a device that can be used for exercising a human's pelvis, hips, knees and ankles by walking (more generally described as ambulating) or running while basically remaining in a relatively fixed position over the treadmill's moving surface. Treadmill exercise can also be of aerobic benefit. Physically impaired or disabled individuals that are confined to a wheelchair or similar mobility aids, but can still safely exercise their pelvis, hips, knees and/or ankles have difficulty getting on and off of the treadmill surface for exercise. They may also experience difficulty in balancing themselves while exercising on the treadmill surface and may require a reduction in body weight forces on the treadmill surface while exercising on the treadmill surface.
During ambulation, the human body's center of mass (COM) is propelled forward. However the body's center of mass (or gravity) also moves vertically and laterally. The total lateral displacement of the center of mass is generally described in the art as tracing a sinusoidal curve with amplitude (AMP in FIG. 1) that can range from around one inch to 5 inches. The greatest lateral excursion of the center of mass occurs at the end of midstance when the body is supported by one leg and begins to move from force absorption at impact to force propulsion forward. Thus, only one full lateral oscillation of the center of gravity (to the right and left) occurs during a gait cycle as illustrated in FIG. 1 which is a view looking down on a treadmill surface with the “FORWARD DIRECTION” arrow facing the front of a typical treadmill where a treadmill console, if used, would be located. Further the degree of lateral displacement (AMP) decreases in going from slow to fast ambulation (for example from 5 inches at 0.1 mile per hour to one inch at 1 mile per hour) and conversely, decreases in going from fast to slow ambulation.
U.S. Pat. No. 5,569,129 discloses a user gait training apparatus that can be used with a treadmill. The apparatus comprises unitary device 21 that can be rolled along the floor to which a harness means 33 can be user connected whereby a user in the harness can be vertically raised or lowered to alter body weight force. The user must put on the harness and body weight force adjustment is accomplished by overhead connection to device 21. The device may be positioned over a treadmill surface so that the user can ambulate on the treadmill surface after having entered the harness. The device allows for forward body center of mass movement. Vertical center of mass movement is restricted by the overhead harness connection to the device and there is no provision for lateral body center of mass movement. Thus gait exercising on a treadmill with the device does not allow for freedom of body (center of mass) movement in all three directions (forward, vertical and lateral) as in a normal human gait during ambulation.
U.S. Pat. No. 8,151,812 B2 discloses a wheeled walker with a seat assembly that a user can dynamically raise or lower in the vertical direction so that the user can adjust the seat assembly's vertical height to mount the wheeled walker and then dynamically raise or lower the seat assembly to adjust the degree of body force weight on the walking surface. Thus the wheeled walker allows for forward body center of mass movement and an adjustable body vertical center of mass movement. At best restricted lateral body center of mass movement can be provided to a limited degree by the caster wheels.
U.S. Pat. No. 6,821,233 B1 has a special harness connected to the user that makes it hard to get in and out of and also the lifting is done overhead. The ability to dynamically stand or to experience normal gait is very limited in the vertical motion, and with no weight-shifting lateral (left and right) movement which are critical at low walking speeds. The harness is very difficult to get in and out of for users that are wheelchair bound and has no access to reach the lower extremities to assist in physical rehabilitation.
U.S. Pat. No. 8,464,716 B2 discloses a differential air pressure system that comprises a user's chamber for maintaining an air pressure differential upon the user's body while exercising on a treadmill surface.
It is one object of the present invention to provide a gait analysis system for a treadmill body support system for gait training exercise on a treadmill where the body support system has means for adjusting the user's body weight force.
It is another object of the present invention to provide a gait analysis system for a body support system for gait training exercise over a fixed surface where the body support system has means for adjusting the user's body weight force.